Metric Assessment of Palatal Index and Gnathic Index in Nigerian Population

Background Understanding the variations of the hard palate is crucial in surgical procedures relating to oral cavity and in individual identification. Similarly, gnathic index assesses the projection of the lower face relative to the upper face. The aim of this study was to analyse the normative data of the palate and gnathic indices in Southern part of Nigeria. Materials and method The cross sectional study analysed 150 dry adult male skulls. Venier caliper and spreading caliper were used to measure palate length and palate breadth as well as basion-nasion length and basion prosthion length. From these measurements, palatal index and gnathic index were calculated. Results For the southeast group, the values of palate breadth, palate length, (mm), palate index (%) and basion-prosthion length, basion nasion length (mm), gnathic index (%) were 38.0 (±3.7), 43.0 (±10.3), 94.1 (±29.7) and 102.2 (±5.5), 103.1 (±5.5), 99.1 ( ±5.5). For the south south group, the values of palate breadth, palate length (mm), palate index (%) and basion-prosthion length, basion-nasion length (mm), gnathic index (%) were 43.2 (±5.3), 51.2 (±5.9), 84.8 (±11.1) and 103.7 (±8.0), 103.1 (±4.7), 100.5 (±5.4). There was a significant difference in the values of palate breadth and palate length in southeast and southsouth groups, but no significant difference in the palate index. There was no significant difference in the gnathic variables in both groups. Conclusions The category of palate index in Southeast and south south Nigerai is brachystaphyline and mesostaphyline respectively while the category of gnathic index in both regions is mesognathous